Severn Trent to make entire transport fleet electric by 2030

Severn Trent to make entire transport fleet electric by 2030

The UK’s second-biggest water company, Severn Trent has joined the Climate Group’s EV100 initiative, pledging to convert 100% of its transport fleet to electric vehicles (EVs) by 2030.

Severn Trent has pledged to deliver net-zero carbon emissions for its operations by 2030

Severn Trent, which serves 4.4 million homes and business customers in England and Wales, will seek to convert its fleet of more than 2,000 vehicles to EVs by 2030 through the initiative. By joining the EV100, Severn Trent will be able to collaborate and discuss EV integrations with a group of likeminded business giants.

Alongside the EV commitment, Severn Trent has pledged to deliver net-zero carbon emissions for its operations by 2030 and generate 100% of its energy needs from renewables in the same time-frame as part of a Triple Carbon Pledge.

In August, the UK’s nine major water and sewerage providers, including Yorkshire Water, Anglian Water and United Utilities committed to planting 11 million trees in order to improve the natural environment across 6,000 hectares of English land as part on an overarching ambition to become a carbon-neutral sector by 2030.

The EV100 has spurred the adoption of 80,000 low-carbon vehicles to date and is now targeting 2.5 million vehicles by 2030. The latest annual report reveals that the 2.5 million vehicles will save 42 million metric tons CO2e, the annual emissions of 11 coal power plants.

Some of the members are targeting 100% zero-emission transport by 2030, while others have pledged to electrify all last-mile deliveries or help all staff make the electric vehicle (EV) switch with their personal or business vehicle.

The coalition of companies, which includes the likes of BT, Ikea and Unilever, have collectively pledged to electrify more than 145,000 vehicles by 2030, according to a report, with the majority prioritising their city-based fleets in a bid to reduce air pollution. In 2019, 82% of EV100 members were charging their EV fleets with 100% renewable power. Almost 10,000 charge points have been installed by the companies.

However, the report also shows that a lack of EV supply is the biggest barrier to faster progress for 79% of EV100 members – up by a third from last year.

The Department for Transport (DfT) has identified a lack of charging infrastructure as one of the three biggest barriers to EV adoption in the UK, along with distance traveled per charge and vehicle cost.

Similarly, Bloomberg New Energy Finance (Bloomberg NEF) predicts that EVs will account for more than half of new car sales by 2040, but that the pace of the shift away from petrol and diesel could be hindered by far slower investment growth in infrastructure.

In July, the UK Government was named as the first government to act as an ambassador for the Climate Group’s EV100 initiative. As an International Ambassador, the UK Government will actively encourage large UK businesses to switch to electric vehicles and use its international network of embassies to call for the same across the world.

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Agriculture, achieving net-zero emissions inquiry launched

Agriculture, achieving net-zero emissions inquiry launched

Agriculture, achieving net-zero emissions inquiry launched

The Environment, Food and Rural Affairs Committee inquiry examines how agriculture can achieve net-zero emissions by 2050 whilst maintaining food production. It will also look at how those affected in farming communities can be supported through the transition fairly.

  • Inquiry: Agriculture, achieving net-zero emissions
  • Environment, Food and Rural Affairs Committee

Reaching ‘net-zero’ greenhouse gas (GHG) emissions

In June 2019, the Government legally committed the UK to reaching ‘net-zero’ greenhouse gas (GHG) emissions by 2050. The agriculture sector accounts for approximately 10% of the UK’s GHG emissions, and many of the options for absorbing carbon emissions such as planting trees or restoring peatland involve changes to the use of land. Therefore, achieving net-zero will pose significant challenges for farming and farming communities.

Climate change

Climate change is also a major risk for UK agriculture. For example, farmers already face water shortages, heat stress on livestock, and crop loss owing to hotter summers. More intense rainfall will mean accelerated soil erosion and more flooding. Sea-level rise could also lead to substantial losses in crop production from low-lying areas.

Reduce agricultural GHGs

The Committee on Climate Change has argued that existing policies are not working, as agriculture’s contribution to UK GHG emissions remains virtually unchanged at 10% since 2008. It has therefore called for stronger action to reduce agricultural GHGs and a better land strategy to fully deal with the challenge of climate change.

Chair’s comments

Neil Parish MP, Chair of the Committee said:

“Climate change is a huge threat to farming in the UK. Agriculture must play its part in getting to net-zero emissions, and that will involve tough choices. But, we must do it in a way that maintains food production in the UK. If we don’t, farmers and the public won’t support the actions that we need to take, and we risk seeing higher emissions in other countries as they produce food to sell to us.
“We therefore want to explore what are the most practical ways that agriculture can achieve net-zero emissions, and how we best support the farming communities who are going to be affected by the transition.”

Terms of reference

1. How could 20% of UK agricultural land be repurposed to increase forest cover, restore peatlands, implement catchment-sensitive farming and enable agricultural diversification, whilst maintaining current levels of food production?

a. Are there other practical and economic ways for the agriculture sector to achieve net zero emissions?

2. How important will the financial payments proposed under the Agriculture Bill be to incentivise actions to reduce, capture and store GHG emissions, and how should the payments system be designed?

3. What support, skills, training and information will land managers need to adapt and thrive; and how should this be provided and funded?

4. How could innovative technologies and farming practices help the agriculture sector achieve net zero? Are they currently commercially viable or is there a viable path to market for them?

5. What impacts would large-scale changes in land-use have on rural communities and how should the transition be managed to achieve sustainable and just economic, environmental and social outcomes?

6. What impact would encouraging a shift in diets towards lower red meat and dairy consumption have on agriculture, and how could any negative impacts be mitigated?

7. How can any reduction in UK-agricultural GHG emissions be achieved without ‘offshoring’ emissions to other countries via increases in the consumption of imported foods in the UK?
The deadline for written submissions is 30 September 2019. Submissions can be submitted through the agriculture, achieving net-zero emissions inquiry page.

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The global transition to cleaner energy

The global transition to cleaner energy

Despite all the progress, we’re still struggling to hit the climate emergency brake.

As you might have heard, the planet is warming up, and in response, people are trying to switch to cleaner energy, to heat it up less, or at least more slowly. So how’s that going?

A report released Monday goes into that question in considerable detail. The Renewables Global Status Report (GSR), released annually by the Renewable Energy Policy Network for the 21st Century (REN21, a think tank), digs into the growth rates of various energy sources, the flows of clean energy investment, and the world’s progress on its sustainability goals.

It is a treasure trove of information. It is also … really long. 250 pages long. So many words!

In an effort to save you, the modern information consumer, precious time, I have gone through the report and extracted the 12 charts and graphs that best tell the story of clean energy as of 2018.

Before we get started, a few background facts on Cleaner Energy

First, we’re still moving in the wrong direction. Global carbon emissions aren’t falling fast enough. In fact, they aren’t falling at all; they were up 1.7 percent in 2018.

Second, we’re still pushing in the wrong direction. Globally, subsidies to fossil fuels were up 11 percent between 2016 and 2017, reaching $300 billion a year.

And third, the effort to clean up is flagging. Total investment in renewable energy (not including hydropower) was $288.9 billion in 2018 — less than fossil fuel subsidies and an 11 percent decrease from 2017.
This is all bad news. The public seems to have the impression that while things are bad, they are finally accelerating toward something better. It’s not true. Collectively, we haven’t even succeeded in reversing direction yet. Despite all the progress described below, we’re still struggling to get ahold of the emergency brake.

That grim context established, let’s jump in.

1) Renewables are pulling ahead in the power sector.

To start with some good news: The shift in the electricity sector has effectively become unstoppable. Globally, more renewable energy capacity has been installed than new fossil fuel and nuclear capacity combined, for four years running. Some 181 GW of new renewables capacity was installed in 2018; it now makes up more than one-third of global installed power capacity. These are mainstream power sources, here to stay.

2) Solar photovoltaics are leading the power sector charge.

As you can see in the chart below, additions of wind and bioenergy capacity have been fairly stable; hydropower is down a bit. The primary reason renewable capacity additions are growing is the rise in solar photovoltaic (PV) panels.
Of the new renewable energy capacity installed in 2018, 55 percent (about 100 GW) was solar PV; wind power had 28 percent, and hydropower 11 percent. The future of the world basically depends on solar continuing to boom.

3) China is leading the solar PV charge.

Why is solar PV rising so rapidly? Mostly China.
The graph below also shows rapid solar PV growth in the US, Japan (thanks to Fukushima and the subsequent shutdown of nuclear), and, more recently, India.

4) In fact, China is leading all the charges.

When it comes to energy, China is usually the biggest and the most, no matter the category. It was responsible for 32 percent of all global renewables investment in 2018. It was the lead investor in, and leads the world in installed capacity of, hydropower, solar PV, and wind.
(A couple of things to note on the graph below: Japan’s unusually high proportion of solar and the comparatively large role of bio-power in the EU and US.)

5) Renewable energy is starting to make a dent in electricity.

All the growth and investments in renewable electricity are starting to add up. Renewables represent more than a third of the world’s installed capacity and, as the graphic below shows, more than 26 percent of global electricity produced.
That said, hydropower, at almost 16 percent, makes up more than half the renewables total. What people tend to think of as renewables, wind and solar, make up only a combined 8 percent. Even in electricity, renewables have a long way to go.

6) Solar is creating the most jobs.

An important aspect of the political economy of renewables: Solar PV creates more jobs. It accounts for the bulk of the world’s renewable energy jobs, despite being a minority of renewable energy capacity. Wind, which leads solar in capacity, creates far fewer jobs. Solar PV is very labor-intensive.

7) But electricity is only part of energy consumption, and not the largest part.

Outside of electricity, good news is harder to come by. Where renewables are 26 percent of global electricity, they represent less than 10 percent (renewable electricity less than 2 percent) of heating and cooling and just 3.3 percent (renewable electricity only 0.3 percent) of transportation energy.

Heating and cooling, at 51 percent of global energy use, mostly run on natural gas and oil. Transportation, at 32 percent of global energy use, mostly runs on gasoline and diesel.

What’s worse, policy is still overbalanced toward power.

There are 169 countries, at the national or state/provincial level, that have passed renewable energy targets. Meanwhile, the report says, “only 47 countries had targets for renewable heating and cooling, while the number of countries with regulatory policies in the sector fell from 21 to 20.” Fewer than a third of all countries worldwide have mandatory building codes, “while 60% of the total energy used in buildings in 2018 occurred in jurisdictions that lacked energy efficiency policies.” Only about a quarter of industrial energy use is covered by industrial energy-efficiency policies.

It’s not much better in transportation, where “fuel economy policies for light-duty vehicles existed in only 40 countries by year’s end and have been largely offset by trends towards larger vehicles.”

Carbon pricing isn’t helping much either. “Carbon pricing remains acutely under-utilised,” the report says. “By the end of 2018, only 44 national governments, 21 states/provinces and 7 cities had implemented carbon pricing policies, covering just 13% of global CO2 emissions.”

This is the story in the US and in the world at large: Renewables are starting to make a dent in electricity, but they are lagging badly everywhere else.

8) Transportation is showing signs of rapid movement toward electrification.

While transportation is still dominated by fossil fuels, a shift is underway. In 2018, “the global number of electric passenger cars increased 63% compared with 2017,” the report says, “and more cities are moving to electric bus fleets.
Here, too, China is outpacing the rest of the world, though shoutout to the tiny country of Norway, whose aggressive EV Policies have it showing up in global statistics.

9) Cities are outpacing countries on clean energy.

There’s a special report within the report about the booming prospects for clean energy in cities worldwide. On average, cities — which represent 65 percent of global energy demand and house more than half the world’s people — use a higher percentage of renewable electricity than countries. Already, there are at least 100 cities around the world using between 90 and 100 percent renewable electricity. At least 230 have set a 100 percent renewable energy goal in at least one sector.

10) Progress is being slowed by fossil fuel subsidies.

Every year, the countries of the G20 get together, decry fossil fuel subsidies, and promise to roll them back. And every year, fossil fuel subsidies grow — rising 11 percent to $300 billion in 2017. “While at least 40 countries have undertaken some level of fossil fuel subsidy reform since 2015,” the report says, “fossil fuel subsidies remained in place in at least 112 countries in 2017, with at least 73 countries providing subsidies of more than USD 100 million each.”

Globally, that is “about double the estimated support for renewable power generation,” the report says.

And that’s just direct subsidies. As my colleague Umair Irfan reported, a recent paper from the IMF estimates total fossil fuel subsidies — both direct, in terms of tax and cash transfers, and indirect, in terms of unpriced environmental damages — reached $5.2 trillion in 2017.
And they are concentrated in countries where they will be difficult to root out.

11) Energy intensity is declining, but not nearly fast enough.

Every climate model that involves humanity hitting its carbon targets involves rapid declines in “energy intensity,” i.e., the amount of energy used to produce a unit of GDP. In theory, if you can reduce energy intensity fast enough, you can offset the natural rise in energy consumption (from population and economic growth) and even cause total energy demand to decline.

In theory, anyway. In reality, global energy intensity has declined just 2.2 percent in the past five years. That has not been enough to offset the rise in global energy demand, which crept up 1.2 percent.

Energy intensity is declining at around 0.4 percent a year. To hit midcentury global decarbonization targets, global energy intensity would need to decline by between 4 and 10 percent a year. That means the world needs to accelerate efficiency and electrification rates by about 10 times.

12) Renewables have a long way to go and a short time to get there.

So what does all this add up to? One (admittedly imperfect) way to mark the progress of renewables is to measure them against total final energy consumption (TFEC), which adds up all energy consumed worldwide.

As of 2017, fossil fuels were still providing about 80 percent of humanity’s energy, which is roughly what they’ve been providing for decades. Excluding traditional biomass, with all its problems around clearcutting, monocropping, and competing with food for land, you’re left with about 13 percent plausibly climate-friendly energy (different people may want to exclude other sources as well, but the larger point stands).

That 13 percent needs to get to 100 percent, or close to it, by 2050 — which is, you will note, just 30 years away. Thirty years ago, I was 17, listening to heavy metal and drinking wine coolers at barn parties. It doesn’t seem like that long ago.
Why is TFEC a flawed measure? Because a huge, huge chunk of that energy consumption is waste. If you look at a Sankey diagram of US Energy Use, which shows the origin and destination of all energy sources, you’ll see that fully two-thirds of the energy that enters the economy ends up “rejected,” i.e., wasted.

That’s because fossil fuel combustion is wasteful. Mining or drilling fossil fuels, transporting them, refining them, burning them, converting them to useful energy, using the energy, disposing of the waste and pollution — at every single stage of that process, there is loss. Burning fossil fuels, for electricity, heat, or transportation, inherently involves enormous levels of waste.

Renewable electricity, which will be the world’s primary energy source if it is to tackle climate change, is simpler. It involves no combustion and fewer conversions generally. Electric motors are simpler than combustion engines, with fewer moving parts, substantially lower maintenance costs, and much higher efficiency. Electrified heating and transportation sectors can be integrated into electricity grid operations, creating system efficiencies.

In short, economies running on renewable electricity will consume less energy because they will waste less energy. They might not consume two-thirds less — waste will never reach zero, and there will be some rebound effect that comes with greater efficiency — but they certainly won’t need to replace the full 80 percent fossil fuels is providing now. And renewable electricity will radically reduce overall energy intensity, even if all it does is substitute for current energy uses.

So the task ahead isn’t as daunting as it might appear from that last chart … but it’s still pretty daunting. Even if overall energy demand falls, all renewables will need to grow, rapidly, across all economies.

The world’s governments urgently need to look past the sparkly good news in the electricity sector and bear down on heating and transportation, where most of the energy is being consumed. Energy systems need to be rapidly electrified and integrated, which will require policy support at every level.

They could start by getting rid of those damn fossil fuel subsidies.

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The climate crisis is affecting people, economic sectors and the environment

The climate crisis is affecting people, economic sectors and the environment

The climate crisis is affecting people, economic sectors and the environment in the European Union.

From increasing heatwaves and droughts to changing precipitation patterns and rising sea levels, the impacts of climate change can already be seen in Europe.

The European Union is dependent on a reliable energy supply.

As part of our joint efforts to make the European energy system more sustainable and less carbon intensive, increasing amounts of the EU’s energy supply comes from renewable sources.

However, many of these sources are also sensitive to weather and climate.

While the focus of European energy policy is rightly on decarbonising the energy system, we must ensure that the investments made into clean energy systems are viable and resilient in a changing climate.

Every part of Europe’s energy system – from primary energy sources and production to transmission and consumption – is affected and potentially vulnerable to climate change and extreme weather events.

However, as the impacts of climate change vary across Europe and across different parts of the energy system, so does the need to adapt accordingly.

In southern Europe, for example, there is a clear risk of decreasing availability of water.

This will affect hydropower and the supply of cooling water needed for thermal power plants.

In Northern Europe, offshore energy production may become more difficult with storms and heatwaves becoming increasingly frequent.
This means current design standards for electricity grids could soon be insufficient and may have to be reconsidered.

Energy system actors are typically more familiar with managing short-term weather and climate variation, while policies on climate change adaptation focus more on long-term change.

Therefore, a resilient energy system is needed to address weather variability, climate variability and climate change across different time scales. There are both synergies and trade-offs between climate change mitigation and adaptation.

For example, better building insulation reduces energy demand and improves comfort of living during extreme heat episodes – a clear win-win solution. In contrast, increasing hydropower capacity in regions with declining water availability can increase the complexity of managing those scarce resources.

“In southern Europe, for example, there is a clear risk of decreasing availability of water. This will affect hydropower and the supply of cooling water needed for thermal power plants”

Climate change is not the only sustainability challenge we face.

Natural ecosystems need land and water, as so do energy technologies.

As part of the energy transition, we need to bear in mind that different low-carbon energy technologies have different impacts on water and land use.

It is critical that we consider policy goals in an integrated way that allows us to maximise benefits and limit adverse side effects.
Many climate adaptation measures make strong business cases for energy companies and other market actors to invest in.

Yet sometimes the societal costs of interruptions in energy supply can be much higher than their direct costs to energy companies.
In these cases, adaptation measures clearly require policy interventions.

The EU and national governments have many options for enhancing the climate resilience of the energy system such as targeted risk assessments, sectoral adaptation plans, reporting obligations and weather and climate services.

The European Commission has developed several decarbonisation scenarios for a climate-neutral Europe by 2050 in its strategy proposal ‘A Clean Planet for All‘.

Moreover, the future development of the EU involves a closer coordination of European and national energy policies.
It also includes reporting requirements that cover climate change mitigation and adaptation.

“Climate change is not the only sustainability challenge we are facing. Natural ecosystems need land and water and so do energy technologies”
The Commission evaluated the EU strategy on climate change adaptation in 2018, highlighting a need to further integrate climate change adaptation in sectoral policies.

It is essential that the development of European and national energy strategies consider the impacts of a changing climate from the beginning.

At the EUSEW Policy Conference, the European Environment Agency is presenting a new report on the adaptation challenges and opportunities for the European energy system.

The report aims to support the efforts of the Commission, national governments and non-state actors involved in energy and adaptation policies.

It also provides valuable information on the climate impacts and adaptation challenges associated with different energy technologies and presents good practice adaptation examples.

It is very encouraging to see that a wide range of stakeholders, from EU and national policymakers to regulators and market actors, are already strengthening the climate resilience of Europe’s energy system.

Businesses play a key role, and they have a clear interest in protecting their assets and minimising costs. By ensuring that European and national energy strategies and plans are aligned and consider the impacts.

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Whitelee Windfarm has been breath of fresh air in efforts to go green

Whitelee Windfarm has been breath of fresh air in efforts to go green

Whitelee Windfarm has been breath of fresh air in efforts to go green

An East Renfrewshire wind farm has been hailed as a “national success story,” a decade on from its official opening.

Whitelee windfarm is the largest onshore wind project in the UK, was created to significantly boost the number of homes powered by renewable energy. It began generating electricity in January 2008 and was officially connected to the National Grid a year later.

Whitelee Windfarm economic, environmental and social benefits

On Friday, a report was published into the economic, environmental and social benefits of the Whitelee Windfarm. It notes that it has generated enough clean, green energy to provide almost 90 per cent of total annual household electricity consumed by Scottish households and businesses.

  • The report also highlights that the wind farm is expected to provide a boost to the UK economy of more than £1billion, including almost £800million in Scotland.
  • The wind farm, in a rural location near Eaglesham, was found to have supported more than 4,000 jobs during its peak years of construction while sustaining around 600 jobs each year through its operation and maintenance.
  • Enough carbon dioxide is saved by the wind farm, the report notes, that it is the equivalent of offsetting two days’ worth of domestic flights to and from Gatwick Airport.

Lindsay McQuade, of ScottishPower Renewables, which owns and operates Whitelee Windfarm said efforts to achieve Scotland’s environmental targets can be achieved through working with industry and are underpinned through legislation.

“We know that onshore wind is the cheapest form of green energy and therefore should be part of Scotland, and the UK’s, low carbon, cost-effective electricity system,” said Ms McQuade.

“Since the passing of the Climate Change Act in 2008, a number of progressive policy measures have been put in place that has enabled Scotland to become coal-free.

“Working with industry and government, the same approach is now needed to ensure we continue to invest in much-needed renewable generation and thereby achieve this objective and support action to tackle the climate emergency facing us.

“Whitelee WindFarm is a great example of what effective policy can deliver. It’s a national success story.

“Every year, it produces the equivalent clean energy to power each and every electric vehicle currently in the UK, preventing over five million tonnes of carbon emissions had this energy come from fossil fuels.

“The decarbonisation of our economy, transport and heating systems can all be achieved through existing technology but that has to include onshore wind if we are to decarbonise by 2050.”

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Anaerobic Digestion (AD) A Renewable Energy Technology

Anaerobic Digestion (AD) A Renewable Energy Technology

Anaerobic Digestion (AD) Reducing Green House Gas (GHG)

Anaerobic digestion (AD) is a process that has been used very successfully in a large number of countries.  Over many years and for a number of purposes. This includes; energy production, nutrient management, waste stabilisation, and pathogen reduction. In all of these uses, it also contributes towards reducing greenhouse gas emissions, both directly and by offset.

It is the only technology currently in the market place that meets the European criteria for second generation bio-fuel production. And can achieve this using a range of mixed wastes, not just purpose-grown biomass. It is also a technology that has been neglected by successive governments. Many of which have climbed on the bandwagons of hydrogen, ethanol and bio-diesel as the renewable bio-fuels of the future. Despite the fact that bio-gas plants using the same substrates give consistently higher net energy yields

Investment in Large Processing Plants

AD will certainly make money for those who invest in large centralised processing plants that accept high energy-value waste inputs. Also charge gate fees, and receive subsidy for the heat or power they produce.

This is not, however, a solution that will maximise the energy potential of the available waste biomass. As by far the largest tonnages of materials are animal slurries and manures produced on farms. Although the energy potential of these per tonne is low. Should they be digested on farms, the overall net energy yield is significant

An even greater benefit may be the fact that digestion can reduce greenhouse gas emissions associated with manure management and improve nutrient management on the farm.

What is Anaerobic Digestion?

Anaerobic digestion (AD) is the controlled natural breakdown of organic materials into methane, carbon dioxide gas and fertiliser.  This takes place naturally or in an anaerobic digester.

AD produces bio-gas, a methane-rich gas that can be used as a fuel and digestate, a source of nutrients that can be used as a fertiliser. Increasingly AD is being used to make the most of our waste by turning it into renewable energy.

How Does the Anaerobic Digestion Process Work?

The process takes place inside an anaerobic digester; a large, sealed tank which is void of oxygen. The air supply is restricted to stimulate ‘anaerobic’ decomposition (as opposed to composting, which takes place in the presence of air). After 20 to 60 days, depending on the configuration and internal temperature of the digester, a methane-rich ‘bio-gas’ is produced.

This gas is commonly used for electricity and heat generation, and may also be upgraded for other applications. The biomass is heated to around the temperature of blood, when it will react with the naturally occurring micro-organisms and bacteria. It goes through four stages

  • Hydrolysis
  • Acidogenesis
  • Acetogenesus
  • Methanogenesis

The end result is that the bio-gas is emitted and a residual co-product is an odour-free ‘digestate’, which is rich in plant-available N, P and K and may be directly spread on the land as a fertiliser. Alternatively, digestate may be further separated or “dewatered” into a solid fraction (typically 25-35% dry matter, enriched in P) which can be used as a soil improver, and a liquid biofertiliser containing much of the ammonium and potassium that can be pumped or transported for land-spreading.

Both the gas and the digestate material can be re-used, therefore making it a very effective way to recycle your waste materials.

Anaerobic Digestion a Renewable Energy Technology

Anaerobic Digestion (AD) is one of a number of renewable energy technologies that have become commercially available to agriculture and industrial sectors.  A key attribute of AD is that it offers multiple environmental and economic benefits, particularly for UK dairy and livestock farms.

Anaerobic Digestion Plants Delivering Low Carbon Energy

Alongside their potential to deliver low carbon energy, on-farm AD plants also appear to be the most promising mitigation measure for reducing greenhouse gas emissions from manures and slurries.

Anaerobic digestion isn’t just some new fad though – this technology has actually been around since the 1800s for the treatment of sewage sludge. But, as concerns about the environment grow, so has the demand for ways to generate renewable energy and, as a result, more and more businesses have been investing in AD over the past few years.

The development of AD in Britain has been relatively slow compared to other renewable energy options, with about 125 plants operational at the end of 2013 and 500 by the autumn of 2017. At Powersystems we estimate 650 plants as of April 2019.

Feed-In Tariff (FIT) to April 2019

Up until April this year, the primary incentive available to farmers was the Feed-In Tariff (FIT), based on the installation of an AD plant if UK farmers were to change the way they handle slurry. The FIT, administered by DECC, did not encourage farmers to reduce pollution, but rather paid for them to generate renewable electricity using a combined heat and power plant (CHP) which runs off bio-gas from the AD process.

Powersystems Supporting Anaerobic Digestion and Combined Heat and Power Projects to Create Electricity

However, combining Anaerobic Digestion with Combined Heat and Power (CHP) to create electricity currently has a number of appreciable difficulties if compared with direct gas use (e.g. in a boiler). These include grid connection issues, significant extra capital/maintenance costs and plant complexity in terms of engineering a system which can continuously produce sufficient quantities of quality gas.

Powersystems can illustrate some of the benefits from on-farm AD  with a number of cases studies which highlight the experience of farmers that we have worked with and how we have helped them to overcome infrastructure challenges.

Read this case study about the Farleigh Wallop AD Plant

Challenges of Slurry Utilisation

The average farmer’s options to fully and economically utilise their slurries in an environmentally friendly manner are further compromised by the fact that:

  • the primary feed-stock (cattle slurry) is generally only available for 6 – 7 months when cows are housed indoors over the winter months
  • sufficient year-round on-farm organic substrates may be limited
  • there are significant regulatory financial penalties imposed for digesting the off-farm substrates (which have to be returned to land, anyway), including those which can be fed to cows

 Barriers to Anaerobic Digestion

Some farmers may not have the option or desire to grow energy crops in order to boost bio-gas output to improve the economics of using AD with CHP, for what is primarily their slurry treatment system, especially if the cost of bought in feed increases in line with fossil fuel costs, putting further pressure on farmers to grow their own crops to feed their cattle.

A further barrier is access to capital. Pollution control and other capital grants have largely been phased out. Banks are not prepared to lend money for a technology with which they are largely unfamiliar and suspicious of.

In addition, the UK AD market has been slow to develop (compared to elsewhere in the EU), so technology suppliers of smaller plant, where margins are smaller, tend not to have a large working capital base themselves, further increasing investment wariness.

Turning Waste Into Renewable Energy

Anaerobic digesters generate significant amounts of energy from agriculture materials and waste products from the food chain. The Coalition Government identified development of Anaerobic Digestion (AD) as an early win in 2010 with a commitment to work towards a ‘zero waste economy’.

Anaerobic Digestion can play an important role as a means of dealing with organic waste and avoiding, by more efficient capture and treatment, the greenhouse gas (GHG) emissions that are associated with its disposal to landfill.

AD also offers other benefits, such as recovering energy and producing valuable biofertilisers. The bio-gas can be used to generate heat and electricity, converted into bio-fuels or cleaned and injected into the gas grid.

Bio Gas

Anaerobic Digestion can be applied to a range of natural biodegradable materials, including food waste, slurry, sewage sludge and manure.

  • This material, known as biomass, is naturally broken down until it emits a new gas – known as bio-gas. Bio-gas is a methane-rich gas, comprising of around 60 per cent methane and 40 per cent carbon dioxide. This gas can then be used to generate energy.
  • Bio-gas can be used directly in engines for Combined Heat and Power (CHP), burned to produce heat, or can be cleaned and used in the same way as natural gas or as a vehicle fuel.
  • Bio gas can be used in stationery engines to generate electricity.
  • After removing the carbon dioxide (and other trace gases using a variety of methods in a process known as upgrading) the remaining methane is known as Renewable Natural Gas or Biomethane.

How the AD process works for Food Waste

Anaerobic digestion is an alternative way of composting food waste, while also producing renewable energy and avoiding carbon emissions. The process is called anaerobic because it takes place in the absence of oxygen in a sealed tank. Like composting, it is a natural process dependent on the micro-organisms that digest organic waste.

  • Collection – Food waste, collected from homes and businesses, is delivered – either directly or via a waste transfer station – to the reception hall of an anaerobic digestion facility.
  • Pre-treatment – First the food waste must be pre-treated to remove contaminants such as packaging and it is also diluted with water. Heating this waste mixture to 70°C for one hour kills all pathogens in the food.
  • Digestion – Now pasteurised, the waste is fed into the anaerobic digester. As with composting, bacteria break down the waste, converting it into biogas and a residue, which is called digestate.
  • Energy – Gas piped from the digester is used to generate electricity and heat.

The great thing about food waste is that it is produced by a community, it’s converted to electricity and it goes back to community again – it’s self-sustaining.


  • Is virtually identical to natural gas, the main difference is that is produced in days, rather than taking millions of years, billions of years ago.
  • The uses for Biomethane are therefore as varied as are those for natural gas, for heating, cooling as a source of chemicals, fertiliser or hydrogen.
  • When used as vehicle fuel, bio methane is without doubt, the world’s cleanest and most environmentally friendly fuel.

Carbon Dioxide

  • Is valued for its properties as an inert gas, for heat transfer and as a solvent.

Feedstock Suitable For use in the AD process can include

  • animal manures and slurries
  • energy crops such as maize or rye-grass silage and fodder beet
  • food processing by-products and pack-house residues
  • food waste from retailers
  • biodegradable household waste

What Are The Benefits?

AD provides many businesses with a way to turn the waste products they inevitable produce into new, clean energy, which can then be used on their own site. It can be utilised by any industry which produces food or sewage waste, including agricultural, sewage and food processing, and there are different sized systems available dependent on the amount of waste produced.

The methane-rich biogas which is generated can be used as a source of renewable energy to power electricity generators and provide heat. It can even be altered further and upgraded to filter out the majority of the carbon dioxide – the end result is bio-methane, which can then be used as vehicle fuel or to provide gas. Plus, the digestate can be used as fertiliser, suitable for organic farming systems.

By utilising anaerobic digestion, you can help reduce the amount of waste which you are sending to landfill. This in turn helps to reduce harmful emissions of harmful greenhouse gases, as biodegradable material which is simply sent to landfill will emit a large amount of methane, and carbon dioxide if it is simply left to rot.

How Widely Used Is This Technique?

The spotlight has fallen on waste over recent years. Currently, England generates around 177 million tonnes of waste a year – a disproportionate amount to what is reused or recycled. The government are trying to put measures in place to move towards a zero waste economy, which means that waste resources are fully valued and everything that can be reused and recycled is.

As part of this, the UK government and the European Union Directive have begun to introduce legal and financial incentives for diverting waste away from landfill, so taking advantage of this technology could even bring financial benefits for your business too.

Additionally, more people are looking to businesses to set an example when it comes to waste management and energy use. By utilising a technology which uses waste to create clean energy, you can help enhance your business’s reputation and values, reflecting your business as a responsible, conscientious company.

By investing in anaerobic digestion for your business, you will be taking a step towards making your business greener, and helping the country meet its waste disposal and energy targets

What does the UK produce that can be used in AD plant process?

The UK produces over 100 million tonnes of organic material that is suitable for treatment by AD. This includes:

  • 90-100 million tonnes of agricultural by-products like manure and slurry
  • 16-18 million tonnes of food waste (from households and industry)
  • 7 million tonnes of dry sewage sludge.

 How much energy can you get from waste?

The amount of energy produced by AD will vary depending on the material that goes into it and the particular type of digester that is used. Digesting 1 tonne of food waste can generate about 300 kWh of energy; slurry is lower yielding and purpose grown crops higher. According to the Renewable Energy Association, if all the UK’s domestic food waste was processed by AD, it would generate enough electricity for 350 000 households.

How much energy could anaerobic digestion generate in the UK?

AD could generate 10-20 TWh of heat and power per year by 2020. To put this in context, the UK’s largest power station Drax sold 27.1 TWh of electricity in 2012. AD could represent 3.8-7.5% of the renewable energy we estimate will be required in 2020.

 How many anaerobic digestion plants are there in the UK? 

AD has been used for many years in the UK by the water industry. It currently treats 66% of the UK’s sewage sludge in AD plants. Beyond the water industry AD in the UK is in its infancy, but growing rapidly. There are currently around 100 non-water industry anaerobic digesters in the UK producing bioenergy. You can see the locations of operational AD plants on the Biogas Map. There are many more digesters that are currently in the ‘planning’ stage of development.

Is digestate the same as compost? 

No. Digestate is not compost, although they have some similar properties.  Compost is produced by aerobic (with air) decomposition of biological material and digestate is produced by anaerobic (without air) decomposition of biological material. They can both be used as fertiliser under specific regulations.

 Does AD smell? 

There is some odour associated with the organic material that goes into a digester. However, AD can actually reduce nuisance odours as waste is delivered in closed vessels and vehicles, received in a closed reception area, and the digestion process takes place in a sealed tank. The digestion of slurry, for example, is significantly less odorous than the common practice of storing slurry in pits.

Is AD right for me? 

This website is a good place to start.  There is an AD cost calculator to look at the economics and there are lots of links to useful information and organisations. The key questions for a potential developer are:

  • Do you have access to sufficient feedstock?
  • Is there a market for the digestate?
  • What do you have in terms of good access, storing and handling facilities?
  • Are you willing to take on high capital project with capital rich initial period (i.e. can delayed returns be absorbed in your cash flow model)

 What are the benefits of AD? 

  • It turns waste into a resource. Instead of sending waste to landfill, we can use it to produce energy and fertiliser.
  • It produces fuel. Bio-gas can be used instead of fossil fuels.
  • Fertiliser is produced. Fertilisers are made from fossil fuels. The digestate from this can replace some synthetic fertilisers.
  • It reduces our carbon footprint.The methane produced during AD is burned as fuel, and therefore releases CO2 into the atmosphere.  Because it comes from biomass, this does not contribute to climate change. However, if the same waste was left to degrade in a landfill site, the methane produced could escape into the atmosphere: methane has a global warming potential 23 times larger than that of CO2. Therefore, harvesting and using methane from biomass can help to prevent climate change.
  • It can benefit many different people.  AD potentially benefits the local community, the environment, industry, farmers and energy entrepreneurs and government.

 What are the drawbacks of AD?

  • AD plants are 24-hour operations and as such they need to be fed regularly. Pumps and other machinery also need to be maintained to ensure production is not interrupted.
  • There can be noisedust, and if there are leaks the potential of smells and environmental contamination. However, these issues are strictly controlled by environmental regulations, so should not occur. The liquid part of the digestate contains nitrates and other chemicals which should not be released to water but which can safely be spread to land or processed for wider use.
  • The use of bio-gas also releases CO2, which is a greenhouse gas. However, this is offset because the bio-gas produced in AD replaces fossil fuels when it is used for heat, power or transport. If the waste were land-filled it would naturally rot and release methane, a potent greenhouse gas.


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